Sorry I forgot to add the pictures of the space. the wall is 120 inches

Are you going to move the air intake?

if we do built ins yes

If storage is your need then The photos you show will work well. Keep it in the lighter tones and also keep in mind that you will have to relocate the return air when doing so.

J Design Group
225 Malaga Ave
Coral Gables, FL 33134
Ph: 305-444-4611
https://www.JDesignGroup.com

I like a portable piece, but I can't think of any source other than RH for something appropriate in size. Here are two examples. Not sure you could get it built for less.

The last place i would build “for storage” is the formal dining room. Relocation of the air return is no simple task to say nothing of the expense. I would search antique shops that carry wood furniture and find a great piece for the room that enhances what looks like a very pretty home. You can fine some beautiful pieces at bargain prices with far better quality than new pieces mass produced today. Bonus, you take it with you when you move!

I would go one step further in favor of adding furniture rather than built-ins......the huge furniture piece is less flexible and very difficult to move ...never mind extremely costly.....perhaps two smaller pieces should be considered...

I wouldn’t do built ins either. Ballard Designs makes some nice wall units that look sort of built in...

Crate and barrel options